Mean salivary soluble CD44 levels were 24.4 ng/mL for HNSCC patients, compared with 9.9 ng/mL for control subjects with benign disease (P < .0001). "After controlling for potential confounders, we found that soluble CD44 levels were elevated in head and neck cancer patients regardless of risk behavior or demographic factors," Dr. Franzmann reported.
Depending on the cut-points and HNSCC site, sensitivity ranged from 62% to 70%, and specificity from 75% to 88%. Fifty percent of patients without invasive disease had elevated soluble CD44 levels that were associated with either the presence of dysplasia or imminent malignant progression.
In the hypermethylation pilot study, 9 of 11 HNSCC patients with low soluble CD44 levels vs none of 11 control subjects demonstrated CD44 promoter hypermethylation. This suggests that in HNSCC patients, when soluble CD44 levels are low, CD44 hypermethylation is usually present. Since controls did not show CD44 hypermethylation, this marker in combination with the soluble CD44 test may significantly increase sensitivity without adversely affecting specificity, Dr. Franzmann suggested.